Preserve base and loffset arguments in resample

[spencerkclark]

While pandas is getting set to remove the base and loffset arguments in resample, we have not had a chance to emit a deprecation warning for them yet in xarray (#7420). This PR preserves their functionality in xarray and should hopefully give users some extra time to adapt. Deprecation warnings for each are added so that we can eventually remove them.

I've taken the liberty to define a TimeResampleGrouper object, since we need some way to carry the loffset argument through the resample chain, even though it will no longer be allowed on the pd.Grouper object. Currently it is not particularly complicated, so hopefully it would be straightforward to adapt to what is envisioned in #6610 (comment).

• closes ⚠️ Nightly upstream-dev CI failed ⚠️: pandas removed deprecated keyword arguments #7266
• Tests added
• User visible changes (including notable bug fixes) are documented in whats-new.rst

[dcherian]

I think the checks on base are backwards? It's raising a warning when base is None which makes the doctests fail.

[keewis]

both the failing upstream-dev CI and the failing docs CI seem to be unrelated to this. The TimeResampleGrouper seems to do something different from the one in #7561, but I think that's up to that PR to figure out (since we don't yet expose it as public API).

So considering that, how much do you think is needed until we can merge this? And can I help with anything?

[dcherian]

TimeResampleGrouper seems to do something different from the one in #7561,

The version in that PR is just a container for the factorize method. I'm waiting for this to get merged before continuing

[dcherian]

Shall we merge?

AFAICT all groupby and resample tests now pass on upstream-dev:

=========================== short test summary info ============================
FAILED xarray/tests/test_backends.py::TestNetCDF4Data::test_roundtrip_cftime_datetime_data - AssertionError: assert 'days since 1-01-01' == 'days since 0001-01-01'
  - days since 0001-01-01
  ?            ---
  + days since 1-01-01
FAILED xarray/tests/test_backends.py::TestNetCDF4ViaDaskData::test_roundtrip_cftime_datetime_data - AssertionError: assert 'days since 1-01-01' == 'days since 0001-01-01'
  - days since 0001-01-01
  ?            ---
  + days since 1-01-01
FAILED xarray/tests/test_backends.py::TestZarrDictStore::test_roundtrip_cftime_datetime_data - AssertionError: assert 'days since 1-01-01' == 'days since 0001-01-01'
  - days since 0001-01-01
  ?            ---
  + days since 1-01-01
FAILED xarray/tests/test_backends.py::TestZarrDirectoryStore::test_roundtrip_cftime_datetime_data - AssertionError: assert 'days since 1-01-01' == 'days since 0001-01-01'
  - days since 0001-01-01
  ?            ---
  + days since 1-01-01
FAILED xarray/tests/test_backends.py::TestZarrKVStoreV3::test_roundtrip_cftime_datetime_data - AssertionError: assert 'days since 1-01-01' == 'days since 0001-01-01'
  - days since 0001-01-01
  ?            ---
  + days since 1-01-01
FAILED xarray/tests/test_backends.py::TestZarrDirectoryStoreV3::test_roundtrip_cftime_datetime_data - AssertionError: assert 'days since 1-01-01' == 'days since 0001-01-01'
  - days since 0001-01-01
  ?            ---
  + days since 1-01-01
FAILED xarray/tests/test_backends.py::TestZarrDirectoryStoreV3::test_write_read_select_write - KeyError: 'var1'
FAILED xarray/tests/test_backends.py::TestZarrDirectoryStoreV3FromPath::test_roundtrip_cftime_datetime_data - AssertionError: assert 'days since 1-01-01' == 'days since 0001-01-01'
  - days since 0001-01-01
  ?            ---
  + days since 1-01-01
FAILED xarray/tests/test_backends.py::TestZarrDirectoryStoreV3FromPath::test_write_read_select_write - KeyError: 'var1'
FAILED xarray/tests/test_backends.py::TestScipyInMemoryData::test_roundtrip_cftime_datetime_data - AssertionError: assert 'days since 1-01-01' == 'days since 0001-01-01'
  - days since 0001-01-01
  ?            ---
  + days since 1-01-01
FAILED xarray/tests/test_backends.py::TestScipyFileObject::test_roundtrip_cftime_datetime_data - AssertionError: assert 'days since 1-01-01' == 'days since 0001-01-01'
  - days since 0001-01-01
  ?            ---
  + days since 1-01-01
FAILED xarray/tests/test_backends.py::TestScipyFilePath::test_roundtrip_cftime_datetime_data - AssertionError: assert 'days since 1-01-01' == 'days since 0001-01-01'
  - days since 0001-01-01
  ?            ---
  + days since 1-01-01
FAILED xarray/tests/test_backends.py::TestNetCDF3ViaNetCDF4Data::test_roundtrip_cftime_datetime_data - AssertionError: assert 'days since 1-01-01' == 'days since 0001-01-01'
  - days since 0001-01-01
  ?            ---
  + days since 1-01-01
FAILED xarray/tests/test_backends.py::TestNetCDF4ClassicViaNetCDF4Data::test_roundtrip_cftime_datetime_data - AssertionError: assert 'days since 1-01-01' == 'days since 0001-01-01'
  - days since 0001-01-01
  ?            ---
  + days since 1-01-01
FAILED xarray/tests/test_backends.py::TestGenericNetCDFData::test_roundtrip_cftime_datetime_data - AssertionError: assert 'days since 1-01-01' == 'days since 0001-01-01'
  - days since 0001-01-01
  ?            ---
  + days since 1-01-01
FAILED xarray/tests/test_backends.py::TestH5NetCDFData::test_roundtrip_cftime_datetime_data - AssertionError: assert 'days since 1-01-01' == 'days since 0001-01-01'
  - days since 0001-01-01
  ?            ---
  + days since 1-01-01
FAILED xarray/tests/test_backends.py::TestH5NetCDFFileObject::test_roundtrip_cftime_datetime_data - AssertionError: assert 'days since 1-01-01' == 'days since 0001-01-01'
  - days since 0001-01-01
  ?            ---
  + days since 1-01-01
FAILED xarray/tests/test_backends.py::TestH5NetCDFViaDaskData::test_roundtrip_cftime_datetime_data - AssertionError: assert 'days since 1-01-01' == 'days since 0001-01-01'
  - days since 0001-01-01
  ?            ---
  + days since 1-01-01
FAILED xarray/tests/test_cftimeindex.py::test_to_datetimeindex_out_of_range[360_day] - Failed: DID NOT RAISE <class 'ValueError'>
FAILED xarray/tests/test_cftimeindex.py::test_to_datetimeindex_out_of_range[365_day] - Failed: DID NOT RAISE <class 'ValueError'>
FAILED xarray/tests/test_cftimeindex.py::test_to_datetimeindex_out_of_range[366_day] - Failed: DID NOT RAISE <class 'ValueError'>
FAILED xarray/tests/test_cftimeindex.py::test_to_datetimeindex_out_of_range[all_leap] - Failed: DID NOT RAISE <class 'ValueError'>
FAILED xarray/tests/test_cftimeindex.py::test_to_datetimeindex_out_of_range[gregorian] - Failed: DID NOT RAISE <class 'ValueError'>
FAILED xarray/tests/test_cftimeindex.py::test_to_datetimeindex_out_of_range[julian] - Failed: DID NOT RAISE <class 'ValueError'>
FAILED xarray/tests/test_cftimeindex.py::test_to_datetimeindex_out_of_range[noleap] - Failed: DID NOT RAISE <class 'ValueError'>
FAILED xarray/tests/test_cftimeindex.py::test_to_datetimeindex_out_of_range[proleptic_gregorian] - Failed: DID NOT RAISE <class 'ValueError'>
FAILED xarray/tests/test_cftimeindex.py::test_to_datetimeindex_out_of_range[standard] - Failed: DID NOT RAISE <class 'ValueError'>
FAILED xarray/tests/test_coding_times.py::test_should_cftime_be_used_source_outside_range - Failed: DID NOT RAISE <class 'ValueError'>
FAILED xarray/tests/test_conventions.py::TestCFEncodedDataStore::test_roundtrip_cftime_datetime_data - AssertionError: assert 'days since 1-01-01' == 'days since 0001-01-01'
  - days since 0001-01-01
  ?            ---
  + days since 1-01-01
FAILED xarray/tests/test_dataarray.py::TestDataArray::test_sel_float - NotImplementedError: float16 indexes are not supported
FAILED xarray/tests/test_dataarray.py::TestDataArray::test_to_and_from_cdms2_sgrid - ValueError: operands could not be broadcast together with shapes (3,) (4,)
FAILED xarray/tests/test_units.py::TestVariable::test_aggregation[int64-method_max] - TypeError: no implementation found for 'numpy.max' on types that implement __array_function__: [<class 'pint.util.Quantity'>]
FAILED xarray/tests/test_units.py::TestVariable::test_aggregation[int64-method_min] - TypeError: no implementation found for 'numpy.min' on types that implement __array_function__: [<class 'pint.util.Quantity'>]
FAILED xarray/tests/test_units.py::TestDataArray::test_aggregation[float64-function_max] - TypeError: no implementation found for 'numpy.max' on types that implement __array_function__: [<class 'pint.util.Quantity'>]
FAILED xarray/tests/test_units.py::TestDataArray::test_aggregation[float64-function_min] - TypeError: no implementation found for 'numpy.min' on types that implement __array_function__: [<class 'pint.util.Quantity'>]
FAILED xarray/tests/test_units.py::TestDataArray::test_aggregation[int64-function_max] - TypeError: no implementation found for 'numpy.max' on types that implement __array_function__: [<class 'pint.util.Quantity'>]
FAILED xarray/tests/test_units.py::TestDataArray::test_aggregation[int64-function_min] - TypeError: no implementation found for 'numpy.min' on types that implement __array_function__: [<class 'pint.util.Quantity'>]
FAILED xarray/tests/test_units.py::TestDataArray::test_aggregation[int64-method_max] - TypeError: no implementation found for 'numpy.max' on types that implement __array_function__: [<class 'pint.util.Quantity'>]
FAILED xarray/tests/test_units.py::TestDataArray::test_aggregation[int64-method_min] - TypeError: no implementation found for 'numpy.min' on types that implement __array_function__: [<class 'pint.util.Quantity'>]
FAILED xarray/tests/test_units.py::TestDataArray::test_unary_operations[float64-round] - TypeError: no implementation found for 'numpy.round' on types that implement __array_function__: [<class 'pint.util.Quantity'>]
FAILED xarray/tests/test_units.py::TestDataArray::test_unary_operations[int64-round] - TypeError: no implementation found for 'numpy.round' on types that implement __array_function__: [<class 'pint.util.Quantity'>]
FAILED xarray/tests/test_units.py::TestDataset::test_aggregation[int64-method_max] - TypeError: no implementation found for 'numpy.max' on types that implement __array_function__: [<class 'pint.util.Quantity'>]
FAILED xarray/tests/test_units.py::TestDataset::test_aggregation[int64-method_min] - TypeError: no implementation found for 'numpy.min' on types that implement __array_function__: [<class 'pint.util.Quantity'>]
= 43 failed, 15089 passed, 1223 skipped, 168 xfailed, 74 xpassed, 473 warnings in 671.46s (0:11:11) =

[spencerkclark]

@keewis and @dcherian indeed I just wanted to give it another once over. I think it should be ready for review now. Thanks for your patience on this!

[keewis]

the docs failure is real, I think we need to update

xarray/doc/user-guide/weather-climate.rst

Line 236 in 821dc24

da.resample(time="81T", closed="right", label="right", base=3).mean()

to use the new parameter (not sure how exactly, though)

[spencerkclark]

Thanks @keewis -- I pushed a fix. The documentation build succeeded. The other build failures look unrelated.

[keewis]

I agree, those do indeed seem unrelated, and I have no idea why the python 3.11 macos CI takes that long to run.

[dcherian]

I was going to suggest adding an example of time offset arithmetic here. But then thought we could just link to docs. But turns out we have no docs on this AFAICT! I'll open an issue (see #7596)